They Gauge More Than Rainfall

During last week's drenching rains here in the Houston area, local bayous, for the most part, stayed within their banks, with only the typical street flooding that comes with big storms. But as Pat Hernandez reports, a team of people was watching the rising water, just in case, thanks to a huge network of sensors that monitor flood levels.

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The rains may have saturated the ground, but area bayous drained with no problem, according to Heather Saucier with the Harris County Flood Control District. She says there is an extensive gauge system on the bayous and many of the tributaries that measure different things.

"They measure rainfall, they can measure water surface elevations in the channels, they can measure wind speed, they can measure pressure, they measaure all different types of things. We are primarily using them to measure rainfall amounts and water surface elevations in the channels. We have a team of people, it's our flood watch team. They are constantly monitoring all 140 of these gauges in the Harris County area."

She says a field crew goes out to inspect the gauges prior to anticipated rainfall. They are calibrated to ensure information gathered is accurate when data is fed back via computer to Flood Control.

"We have gauge stations, and we've got sensors and transmitters, and all of this information is fed through the air, through servers, and goes to agencies like the Harris County Flood Control District, the Office of Emergency Management, National Weather Service uses the gauge system as well, and of course we feed all the information to the news media so that it can be delivered to the public in real time."

A giant map of Harris County with lights positioned on the bayous and watersheds is still located at the OEM at TranStar, but Saucier says residents can access a similar map through the OEM website (http://www.hcoem.org/HCRainfall.aspx).

"When you do that, it will bring up all of the gauge information. It will let you know where water levels are in the channel, it will let you know where the top of the bank is, so you have a good idea of how much farther the water has to rise before reaching the top of the banks, and all that information is sent to us from the gauges. But it is our job to have a team of people who are constantly monitoring these gauges."

Most people can't see the gauges, but Saucier says Flood Control knows exactly where they are located because of the information they contain.

"When we get rainfall information, and when we get information about how quickly water is rising in our bayous, we can estimate well, if we had 'x' amount of rain, we know that the water would spill over and most likely reach these certain areas. That's how we define flood plains. That's how we locate them and define their boundaries."

She says accurate information is important for the public's safety, but it makes the Flood Control District design and build better projects.